Citizen Scientists Making Incredible Discoveries

April 22, 2011: "Somewhere, something incredible is waiting to be known," wrote Carl Sagan.

And now you can be the one to find it, thanks to Zooniverse, a unique citizen science website. Zooniverse volunteers, who call themselves "Zooites," are working on a project called Galaxy Zoo, classifying distant galaxies imaged by NASA's Hubble Space Telescope.1

"Not only are people better than computers at detecting the subtleties that differentiate galaxies, they can do things computers can't do, like spot things that just look interesting," explains Zooniverse director Chris Lintott, an astronomer at the University of Oxford.

In this image, the Voorwerp floats near a spiral galaxy. Credit: NASA/ESA Hubble Space Telescope

When van Arkel noticed this unusual greenish object and posted an image of it on the Galaxy Zoo forum, not even the experts knew what it was.2 They named it "Voorwerp," Dutch for "object."

Another group of Zooites found green "peas" in theirs, and dubbed themselves the "Peas-Corp."

The peas turned out to be small, round green galaxies about a tenth the size of the Milky Way. These are now believed to be the most efficient star factories in the universe, forming huge numbers of stars in a hurry. "It was easy to find 'peas' by computer once we knew they were there, but without the human factor we'd never have noticed them," says Lintott.

Lintott started Zooniverse in 2007 to solve a very large and unique problem: "I had too many galaxies on my hands," he explains.

Lintott was faced with classifying, by shape, one million galaxies imaged by the Sloan Digital Sky Survey. First he did what any self-respecting scientist would do.

"I asked a graduate student to classify them."

The student was good at it, but after he catalogued 50,000 images, it was obvious he needed help – a lot of help -- sorting the other 950,000. The solution came to Lintott and the very relieved student while they were sitting in a pub.

"We were blown away by the response. We had so many hits that our web server crashed on the first morning!"

They quickly solved the server problem and the project took off. With the Hubble Space Telescope, Galaxy Zoo is taking volunteers deeper into the cosmos than ever before. And the Zooniverse team has proven that the Zooites' classifications are as good as those by professional astronomers.

"Their contributions are extremely important," says Lintott. "They're helping us learn how galaxies form and evolve. And they take their work seriously."

But that doesn't prevent them from bringing a sense of adventure and just sheer fun to the research.

"Not long ago some Zooites asked us to take them on a pilgrimage to Zooniverse's birthplace. There was quite a celebration at the pub that night!"3

After Galaxy Zoo kicked off, scientists began approaching Lintott at conferences asking for help. "They realized that we'd found a great way to sort a lot of data fast."

(1) In earlier phases of the project, volunteers classified images from other telescopes such as the Sloan Digital Sky Survey.

(2) Researchers took follow-up telescope observations of the "Voorwerp."According to an American Astronomical Society press release: "One of the strangest space objects ever seen is being scrutinized by the penetrating vision of the NASA/ESA Hubble Space Telescope. A mysterious, glowing green blob of gas is floating in space near a spiral galaxy. Hubble uncovered delicate filaments of gas and a pocket of young star clusters in the giant object, which is the size of the Milky Way. The Hubble revelations are the latest finds in an ongoing probe of Hanny's Voorwerp …In the sharpest view yet of Hanny’s Voorwerp, Hubble’s Wide Field Camera 3 and Advanced Camera for Surveys have uncovered star birth in a region of the green object that faces the spiral galaxy IC 2497 — a bright, energetic object that is powered by a black hole."

(3) Zooniverse blog comments are another indication of the volunteers' sometimes playful approach: "When I'm on @galaxyzoo I like to pretend I'm a vengeful deity, discarding galaxies ... Is this wrong?"